/*
* 带密钥的md5算法库md5lib.h共有下列函数：
*
* char* MDString (char *);
* 输入任意一个字符串，经过md5运算后，返回32个字符长的字符串
*
* char* MDFile (char *);
* 输入任意一个文件名，文件内容经过md5运算后，返回32个字符长的字符串
*
* char* hmac_md5(char* text, char* key);
* 输入任意一个字符串text,和一个用做密钥的字符串key,
* 经过hmac_md5算法处理，返回处理结果：一个定长字符串（32个字符）
*/

/* MD5lib.h - md5 library
*
* Copyright (C) 1990-2, RSA Data Security, Inc. Created 1990. All
* rights reserved.

* RSA Data Security, Inc. makes no representations concerning either
* the merchantability of this software or the suitability of this
* software for any particular purpose. It is provided "as is"
* without express or implied warranty of any kind.

* These notices must be retained in any copies of any part of this
* documentation and/or software.

* The following makes MD default to MD5 if it has not already been
* defined with C compiler flags.
*/
#include <stdio.h>
#include <time.h>
#include <string.h>

#define MD 5

/* GLOBAL.H - RSAREF types and constants

* PROTOTYPES should be set to one if and only if the compiler supports
* function argument prototyping.
* The following makes PROTOTYPES default to 0 if it has not already
* been defined with C compiler flags.
*/

#ifndef PROTOTYPES
#define PROTOTYPES 1
#endif

typedef unsigned char *POINTER; /* POINTER defines a generic pointer type */
typedef unsigned short int UINT2; /* UINT2 defines a two byte word */
typedef unsigned long int UINT4; /* UINT4 defines a four byte word */

/* PROTO_LIST is defined depending on how PROTOTYPES is defined above.
   If using PROTOTYPES, then PROTO_LIST returns the list, otherwise it returns an empty list. */

#if PROTOTYPES
#define PROTO_LIST(list) list
#else
#define PROTO_LIST(list) ()
#endif

/* Length of test block, number of test blocks. */
#define TEST_BLOCK_LEN 1000
#define TEST_BLOCK_COUNT 1000

/* Constants for MD5Transform routine. */
#define S11 7
#define S12 12
#define S13 17
#define S14 22
#define S21 5
#define S22 9
#define S23 14
#define S24 20
#define S31 4
#define S32 11
#define S33 16
#define S34 23
#define S41 6
#define S42 10
#define S43 15
#define S44 21

char* MDString PROTO_LIST ((char *));
char* MDFile PROTO_LIST ((char *));
char* hmac_md5(char* text, char* key);

typedef struct {
    UINT4 state[4];    /* state (ABCD) */
    UINT4 count[2];        /* number of bits, modulo 2^64 (lsb first) */
    unsigned char buffer[64]; /* input buffer */
} MD5_CTX;

static unsigned char PADDING[64] = {
    0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};

/* F, G, H and I are basic MD5 functions. */
#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
#define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
#define H(x, y, z) ((x) ^ (y) ^ (z))
#define I(x, y, z) ((y) ^ ((x) | (~z)))

/* ROTATE_LEFT rotates x left n bits. */
#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))

/* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
   Rotation is separate from addition to prevent recomputation. */
#define FF(a, b, c, d, x, s, ac) { \
    (a) += F ((b), (c), (d)) + (x) + (UINT4)(ac); \
    (a) = ROTATE_LEFT ((a), (s)); \
    (a) += (b); \
}
#define GG(a, b, c, d, x, s, ac) { \
    (a) += G ((b), (c), (d)) + (x) + (UINT4)(ac); \
    (a) = ROTATE_LEFT ((a), (s)); \
    (a) += (b); \
}
#define HH(a, b, c, d, x, s, ac) { \
    (a) += H ((b), (c), (d)) + (x) + (UINT4)(ac); \
    (a) = ROTATE_LEFT ((a), (s)); \
    (a) += (b); \
}
#define II(a, b, c, d, x, s, ac) { \
    (a) += I ((b), (c), (d)) + (x) + (UINT4)(ac); \
    (a) = ROTATE_LEFT ((a), (s)); \
    (a) += (b); \
}

void MD5Init (MD5_CTX *context);
void MD5Update(MD5_CTX *context, unsigned char *input,unsigned int inputLen);

void MD5Final (unsigned char digest[16], MD5_CTX *context);
static void MD5Transform (UINT4 [4], unsigned char [64]) ;
static void Encode(unsigned char *, UINT4 *, unsigned int);
static void Decode (UINT4 *, unsigned char *, unsigned int);
static void MD5_memcpy(POINTER, POINTER, unsigned int);
static void MD5_memset(POINTER, int, unsigned int);

/* MD5 initialization. Begins an MD5 operation, writing a new context. */
void MD5Init (MD5_CTX *context) /* context */
{
    context->count[0] = context->count[1] = 0;
    /* Load magic initialization constants. */
    context->state[0] = 0x67452301;
    context->state[1] = 0xefcdab89;
    context->state[2] = 0x98badcfe;
    context->state[3] = 0x10325476;
}

/* MD5 block update operation. Continues an MD5 message-digest
   operation, processing another message block, and updating the context. */
void MD5Update (MD5_CTX *context, unsigned char *input, unsigned int inputLen)
    /* context */ /* input block */ /* length of input block */
{
    unsigned int i, index, partLen;

    /* Compute number of bytes mod 64 */
    index = (unsigned int)((context->count[0] >> 3) & 0x3F);

    /* Update number of bits */
    if ((context->count[0] += ((UINT4)inputLen << 3)) < ((UINT4)inputLen << 3))
        context->count[1]++;
    context->count[1] += ((UINT4)inputLen >> 29);

    partLen = 64 - index;

    /* Transform as many times as possible. */
    if (inputLen >= partLen)
    {
        MD5_memcpy ((POINTER)&context->buffer[index], (POINTER)input, partLen);
        MD5Transform (context->state, context->buffer);

        for (i = partLen; i + 63 < inputLen; i += 64)
            MD5Transform (context->state, &input[i]);
        index = 0;
    }
    else
        i = 0;

    /* Buffer remaining input */
    MD5_memcpy ((POINTER)&context->buffer[index], (POINTER)&input[i], inputLen-i);
}

/* MD5 finalization. Ends an MD5 message-digest operation, writing the
   the message digest and zeroizing the context. */
void MD5Final (unsigned char digest[16], MD5_CTX *context)
    /* message digest */ /* context */
{
    unsigned char bits[8];
    unsigned int index, padLen;

    /* Save number of bits */
    Encode (bits, context->count, 8);

    /* Pad out to 56 mod 64.*/
    index = (unsigned int)((context->count[0] >> 3) & 0x3f);
    padLen = (index < 56) ? (56 - index) : (120 - index);
    MD5Update (context,(unsigned char*) PADDING, padLen);

    /* Append length (before padding) */
    MD5Update (context, bits, 8);
    /* Store state in digest */
    Encode (digest, context->state, 16);

    /* Zeroize sensitive information.*/
    MD5_memset ((POINTER)context, 0, sizeof (*context));
}

/* MD5 basic transformation. Transforms state based on block. */
static void MD5Transform (UINT4 state[4], unsigned char block[64])
{
//    int i=0;
    UINT4 a = state[0], b = state[1], c = state[2], d = state[3], x[16];
    Decode (x, block, 64);

    /* Round 1 */
    FF (a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
    FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
    FF (c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
    FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
    FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
    FF (d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
    FF (c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
    FF (b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
    FF (a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
    FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
    FF (c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
    FF (b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
    FF (a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
    FF (d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
    FF (c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
    FF (b, c, d, a, x[15], S14, 0x49b40821); /* 16 */

    /* Round 2 */
    GG (a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
    GG (d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
    GG (c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
    GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
    GG (a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
    GG (d, a, b, c, x[10], S22, 0x2441453); /* 22 */
    GG (c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
    GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
    GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
    GG (d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
    GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */
    GG (b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
    GG (a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
    GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
    GG (c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
    GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */

    /* Round 3 */
    HH (a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
    HH (d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
    HH (c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
    HH (b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
    HH (a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
    HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
    HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
    HH (b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
    HH (a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
    HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
    HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
    HH (b, c, d, a, x[ 6], S34, 0x4881d05); /* 44 */
    HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
    HH (d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
    HH (c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
    HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */

    /* Round 4 */
    II (a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
    II (d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
    II (c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
    II (b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
    II (a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
    II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
    II (c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
    II (b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
    II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
    II (d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
    II (c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
    II (b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
    II (a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
    II (d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
    II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
    II (b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */

    state[0] += a;
    state[1] += b;
    state[2] += c;
    state[3] += d;

    /* Zeroize sensitive information. */
    MD5_memset ((POINTER)x, 0, sizeof (x));
}

/* Encodes input (UINT4) into output (unsigned char). Assumes len is
   a multiple of 4. */
static void Encode (unsigned char *output,UINT4 *input,unsigned int len)
{
    unsigned int i, j;

    for (i = 0, j = 0; j < len; i++, j += 4)
    {
        output[j] = (unsigned char)(input[i] & 0xff);
        output[j+1] = (unsigned char)((input[i] >> 8) & 0xff);
        output[j+2] = (unsigned char)((input[i] >> 16) & 0xff);
        output[j+3] = (unsigned char)((input[i] >> 24) & 0xff);
    }
}

/* Decodes input (unsigned char) into output (UINT4). Assumes len is a multiple of 4. */
static void Decode (UINT4 *output,unsigned char *input,unsigned int len)
{
    unsigned int i, j;

    for (i = 0, j = 0; j < len; i++, j += 4)
        output[i] = ((UINT4)input[j]) | (((UINT4)input[j+1]) << 8) |
            (((UINT4)input[j+2]) << 16) | (((UINT4)input[j+3]) << 24);
}

/* Note: Replace "for loop" with standard memcpy if possible. */
static void MD5_memcpy (POINTER output,POINTER input,unsigned int len)
{
    unsigned int i;

    for (i = 0; i < len; i++)
        output[i] = input[i];
}

/* Note: Replace "for loop" with standard memset if possible. */
static void MD5_memset (POINTER output,int value,unsigned int len)
{
    unsigned int i;

    for (i = 0; i < len; i++)
        ((char *)output)[i] = (char)value;
}

/* Digests a string and prints the result. */
char* MDString (char *string)
{
    MD5_CTX context;
    unsigned char digest[16];
    char output1[32];
    static char output[33]={""};
    unsigned int len = strlen (string);
    int i;
    MD5Init (&context);
    MD5Update (&context, (unsigned char*)string, len);
    MD5Final (digest, &context);

    for (i = 0; i < 16; i++)
    {
        sprintf(&(output1[2*i]),"%02x",(unsigned char)digest[i]);
        sprintf(&(output1[2*i+1]),"%02x",(unsigned char)(digest[i]<<4));
    }
    for(i=0;i<32;i++)
        output[i]=output1[i];
    return output;
}


/* Digests a file and prints the result. */
char* MDFile(char *filename)
{
    static char output[33]={""};
    FILE *file;
    MD5_CTX context;
    int i, len;
    unsigned char buffer[1024], digest[16];
    char output1[32];
    if ((file = fopen (filename, "rb")) == NULL)
    {
        printf ("%s can't be openedn", filename);
        return 0;
    }
    else
    {
        MD5Init (&context);
        while ( (len = fread (buffer, 1, 1024, file)) )
            MD5Update (&context, buffer, len);
        MD5Final (digest, &context);
        fclose (file);
        for (i = 0; i < 16; i++)
        {
            sprintf(&(output1[2*i]),"%02x",(unsigned char)digest[i]);
            sprintf(&(output1[2*i+1]),"%02x",(unsigned char)(digest[i]<<4));
        }
        for(i=0;i<32;i++)
            output[i]=output1[i];
        return output;
    }
}

char* hmac_md5(char* text,char* key)
{
    char digest[16];
    char output1[32];
    static char output[33]={""};
    MD5_CTX context;
    unsigned char k_ipad[65]; /* inner padding -key XORd with ipad */
    unsigned char k_opad[65]; /* outer padding -key XORd with opad */
    unsigned char tk[16];
    int i;
    int text_len = strlen (text);
    int key_len=strlen(key);
    /* if key is longer than 64 bytes reset it to key=MD5(key) */
    if (key_len > 64)
    {
        MD5_CTX tctx;
        MD5Init(&tctx);
        MD5Update(&tctx,(unsigned char*) key, key_len);
        MD5Final(tk, &tctx);
        key = (char*)tk;
        key_len = 16;
    }

    /*
    * the HMAC_MD5 transform looks like:
    *
    * MD5(K XOR opad, MD5(K XOR ipad, text))
    *
    * where K is an n byte key
    * ipad is the byte 0x36 repeated 64 times
    * opad is the byte 0x5c repeated 64 times
    * and text is the data being protected
    */

    /* start out by storing key in pads */

    /* bzero( k_ipad, sizeof k_ipad);
       bzero( k_opad, sizeof k_opad);
       */

    for(i=0;i<65;i++)
        k_ipad[i]=(unsigned char)0;
    for(i=0;i<65;i++)
        k_opad[i]=(unsigned char)0;

    /* bcopy( key, k_ipad, key_len);
       bcopy( key, k_opad, key_len);
       */
    for(i=0;i<key_len;i++)
    {
        k_ipad[i]=(unsigned char)key[i];
        k_opad[i]=(unsigned char)key[i];
    }

    /* XOR key with ipad and opad values */
    for (i=0; i<64; i++)
    {
        k_ipad[i] ^= 0x36;
        k_opad[i] ^= 0x5c;
    }
    /* perform inner MD5 */
    MD5Init(&context); /* init context for 1st pass */
    MD5Update(&context, k_ipad, 64); /* start with inner pad */
    MD5Update(&context, (unsigned char*)text, text_len); /* then text of datagram */
    MD5Final((unsigned char*)digest, &context);          /* finish up 1st pass */
    /* perform outer MD5 */
    MD5Init(&context); /* init context for 2nd * pass */
    MD5Update(&context, k_opad, 64); /* start with outer pad */
    MD5Update(&context,(unsigned char*) digest, 16);     /* then results of 1st hash */
    MD5Final((unsigned char*)digest, &context);          /* finish up 2nd pass */
    for (i = 0; i < 16; i++)
    {
        sprintf(&(output1[2*i]),"%02x",(unsigned char)digest[i]);
        sprintf(&(output1[2*i+1]),"%02x",(unsigned char)(digest[i]<<4));
    }
    for(i=0;i<32;i++)
        output[i]=output1[i];
    return output;    
}


